*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
.a1{
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: space-evenly;
    flex-wrap: wrap;
    align-items: flex-start;
    .tob{
        width: 100%;
        height: 37%;

        display: flex;
        justify-content: space-evenly;
        align-content: stretch;
    }
    .asw{
        width: 100%;
        height: 70%;
        display: flex;
        justify-content: space-around;
        .fence{
            width: 30%;
            height: 100%;
            display: flex;
            flex-wrap: wrap;
        }
    }
}
.tubiao{
    width: 200px;
    height: 200px;
    border: 1px solid rgb(0, 0, 0);
}